Stacking paperboard lug box



Nov. 17, 1964 J. P. HAMILTON STACKING PAPERBOARD LUG BOX 3 Sheets-Sheet1 Filed June 26, 1962 INVENTOR. v JQSEPH PO/QTOLA HAMILTON ATTORNEYSNov. 17, 1964 J. P. HAMILTON STACKING PAPERBOARD LUG BOX 3 Sheets-Sheet2 Filed June 26, 1962 FIG 3 INVEN TOR.

JOSEPH POI? TOLA H4M/L T ON BY ATTORNEYS Nov. '17, 1964 J. P. HAMILTONSTACKING PAPERBOARD LUG BOX 3 Sheets-Sheet 3 Filed June 26, 1962INVENTOR.

JOSEPH PORTOLA HAM/L TON 9 1.. nuli 1- United States Patent G 3,157,346STACKING PAPERBQARD LUG BGX Joseph Portola Hamilton, Emeryville,Calii'l, assignor to American Box Corporation of California, SanFrancisco, Califi, a corporation of California Filed June 26, 1962, Ser.No. 285,446 4 Claims. (Cl. 229-23) This invention relates to afiberboard lug box and the like, and has for one of its objects theprovision of a fiberboard box that is adapted to better resist collapsethan heretofore, under compression, such as occurs in the lower boxes ofa stack of loaded boxes.

Another object of the invention is the provision of a fiberboard boxthat is adapted to be shipped flat, or in a collapsed position, andlater set up for use, and which box is provided with reinforced endwalls and means for holding superposed boxes against shifting laterallyrelative to each other in any direction.

An additional object of the invention is the provision of a foldablefiberboard box having a structure that provides for better ventilationof the interior of superposed boxes than heretofore.

Still further objects of the invention are the provision of; improvedlocking means for locking the boxes in setup position; improved end wallstructure providing for greater strength than heretofore; a moreeconomically made structure in a lug box having the desired strength forwithstanding collapse under the compression force of loaded boxessupported thereon when subjected to changes in normal atmospherichumidity.

Other objects and advantages will appear in the description anddrawings.

In the drawings, FIG. 1 is a plan view of a blank from which one portionof the box is to be formed.

FIG. 2 is a fragmentary plan view of one end portion of a blank that issimilar to that of FIG. 1 but modified along opposite end portions. Theportion shown in FIG. 2 corresponds in position to the lower portion ofthe blank of FIG. 1 and the upper end of the blank of FIG. 2, if shown,would have the same structure as seen in FIG. 2.

FIG. 3 is a plan view of a second blank adapted to be used with theblank of FIG. 1 to overlie the latter centrally thereof.

FIG. 4 is a fragmentary plan view of one end portion of a blank that issimilar to that of FIG. 3 but modified for use with the modified blankof FIG. 2.

FIG. 5 is an isometric view of the blanks of FIGS. 1 and 3 securedtogether preparatory to forming the box, with several portions of theassembly partially folded upwardly.

FIG. 6 is an isometric view of the blanks of FIGS. 1-

and 3 substantially folded to form the box, but with certain parts stillextended so as to reveal interior structure.

FIG. 7 is an enlarged cross sectional view taken along line 7-7 of FIG.6.

FIG. *8 is an isometric view that is similar to that of FIG. 6 but whichview is of the modified form of the invention that is produced from theblanks of FIGS. 2 and 4. The view is partly broken away to adapt it tothe sheet.

In detail, referring to the blank of FIG. 1, this blank 3,157,346Patented Nov. 17, 1964 Equally spaced from the pair of creases 1, at thesides thereof outwardly of the bottom panel 2, are folding creases 3that are parallel with the creases 1, each crease 3 being relativelyclose to the crease 1 that is adjacent thereto. Thus a narrow panel 4 isdisposed between each crease 1 and folding crease- 3 that is adjacentthereto.

These narrow panels 4 join the side walls of the box to the bottom panel2, hence they extend longitudinally of the box, and parallel oppositefree end edges 5 extend between the ends of the creases 3 at thecorresponding ends of said creases 3,, which free end edges define theends of the bottom panel 2.

Outwardly of the pair of creases 3, and integral with the narrow panels4 are corresponding side wall panels 6.

Folding creases 7 form the junctures between the outer side wall panels6, and top panels 8, the latter being alike, and in the finished boxthese will extend over the bottom wall 2 a distance equal to theirrespective widths.

The panels 8 terminate in outer free edges 9 that may be parallel withcreases 7, or scolloped or of any other desired contour, and these freeedges define end edges of the central portion of the blank.

Referring to the panels 6, it is seen that these panels are integrallyconnected at their ends with end sections generally designated 11 alongfolding creases 10.

These end sections 11 are alike, and each comprises three panels 13, 14,15 in a row, "in which the panel 14 at each end of each outer side wallpanel 6 is the central panel in each row.

There are four separate sections 11, as seen in FIG. 1. The panels 13are like each other, and each of the panels 15 are alike. These willlater be described more in detail.

In the blank of FIG. 1 the panels 13 are integral with the panels 14along folding creases 16 that, in turn, are parallel with the creases 1,3 and each crease 16 is in outward projection of and in alignment with asubstantial medial line through each narrow panel 4.

The panels 15 are outwardly of the opposite ends of each ofthe toppanels 8, and are separated from said top panels 8 by cuts 17 that arein alignment with the free end edges 5 of the bottom panel 2. At thispoint it may be noted that the folding creases 10 at the ends of theside wall panels 6 are slightly offset toward each other relative to thefree end edges 5 and cuts 17. The reason for this will appear later on.

A pair of parallel relatively closely spaced folding creases 18 that areparallel with the folding crease 16 in the same section define two ofthe edges of a narrow strip 19 that joins the adjacent panels 14, 15 ofeach section 11'. These creases 18 are equally spaced at opposite sidesof a line in extension of each crease 7 that is at the juncture betweeneach side wall panel 6 and the top panel 8 adjoining it.

The outer free edges 20 that are along the panels 13-15 of each set 9are straight and uninterrupted. However, the adjacent panels 13 at theends of the bottom panel 2, and along free end edges 5 are spaced apart,and terminate in free edges 23 that are at right angles to edges 20, andalong each edge 23 a rectangular tab 24 projects into the space betweenthe adjacent panels 13, which tabs are equally spaced from the edges 5at each end of bottom wall 2, and each such tab is preferably closer toedge 5 than to the outer edge 20 of the sections 13-15.

The crease 18 ofeach pair thereof that is closest to the central panel14 of each section 11 does not extend uninterruptedly between cut 17 andthe outer free edge 20 of each section, but is interrupted by cuts thatform an elongated rectangular tab 25, which tab extends across theadjacent crease 18 and into the adjacent panel 15 to a point aboutmidway between the panel 15 and its free 3 edge 26 that is substantiallyin alignment with the free edge 9 of the blank.

Each tab 25 extends at a right angle to the creases 18 and each tab isat the same distance from the cut 17 that is adjacent thereto as eachtab 24 is distant from the adjacent free end edge of the bottom panel 2.Also the width of each tab 25 is substantially the same as the width ofeach tab 24 in the same dimension, or in the same direction as edge 23or creases 18.

Offset relative to each pair of folding creases 18 in a direction towardthe outer free end of each tab 25, is a pair of parallel, closely spacedfolding creases 27, which creases are parallel to creases 18 that areadjacent thereto.

The distance between each pair of creases 18 is such that the panel 13will lie fiat between the panels 14, 15 when each panel 13 is foldedupwardly (as seen in FIG. 1), over and against the central panel 14, andpanel 15 is then folded upwardly and over and against the panel 13. FIG.5 shows two such sections, after folding, the section at the upper righthand corner being fiat with the bottom panel 2, the latter being coveredin FIG. 5 by another blank, as will be described later on.

The distance between the edge 23 of each panel 13 and the crease 16adjacent thereto, is substantially equal to the distance between creases16, and the crease 18 nearest thereto, while the distance between crease16 and the crease 17 in tab that is nearest thereto is substantiallyequal to the distance between the outer free end edge of tab 24 and thecrease 16, therefore, when the panel 13 is folded against panel 14, theouter free end of tab 24 will be at the above-mentioned crease 27, andupon folding panel 15 over panel 13, the tab 25 will project beyond thenarrow strip 19 between creases 18, yet the outer end portion of tab 25beyond creases 47 may be folded over the projecting tab 24, as seen inFIG. 5.

Two elongated slots are formed along each crease 7. These areventilation slots in the finished box, and one or more slots 31 areformed in each narrow panel 4 for the same purpose.

On each end of each top panel 8 an outwardly projecting tab 32 isformed. These tabs 32 each have one tapered edge 33 to facilitate theirentry into slots that are provided in the blank of FIG. 3 that is partof the finished box when said blank is assembled with the blank of FIG.1 to form the box. This will later be described. Each tab 32 extendsinto each top panel 8 a short distance, and the base edge of each tab isdefined by a folding crease 34. Each tab 32 extends into each panel 15,and therefore interrupts the cut 17 that is between the top panel 8 andeach panel 15.

A small triangular portion of the blank is stamped out at the end ofeach narrow panel 4, to form a triangular opening 35, having its base inextension of the free edge 5 of the bottom panel, and the apex of eachopening 35 is on the line of each crease 16, and at the end of each suchcrease that is adjacent to each narrow panel 4. The reason for thisopening is to enable the narrow panels 4 to extend slantingly upwardlywhen the box is formed so that the ventilating openings 31 will not beblocked off when the boxes are in adjoining stacks. This is a highlydesirable feature in a box of this type.

Along each of the free end edges 5 of the bottom wall or panel 2 is apair of square, outwardly opening notches or recesses 36. These areequally spaced from the ends of creases 1, and will cooperate withcertain structure in the panel of FIG. 3 when the latter is assembledwith the panel of FIG. 1.

Also, along the edge 26 of each panel 15 is a relatively shallow squarenotch or outwardly opening recess 37 that is adapted to cooperate withthe notch 36 that is nearest thereto and with structure in the panel ofFIG. 3 when the box is assembled. Adjacent to each notch 37, each panel15 is cut away to form a slanted edge 38 that is adapted to engage theupper surface of the narrow panel 4 when the box is set up with saidnarrow panel in an inclined position, as has already been mentioned, andan opening 39 is formed along each crease 16 adjacent to each opening35, which opening extends into panels 13, 14.

Referring to the blank of FIG. 3, this blank is elongated so as toextend across and over the bottom panel 2 of the blank of FIG. 1, andhas a central portion 40 that is of the same width as the bottom panel2, hence when the central portion 40 is positioned on the bottom panel 2its free edges will be along and be parallel with the folding creases 1,to become the upper layer of the bottom of the carton, while panel 2will be the lower layer.

Parallel folding creases 43 extend transversely across the panel of FIG.3 and are spaced apart a distance substantially equal to the distancebetween the free end edge 5 of the bottom panel 2.

Outwardly of the pair of folding creases 43 are corresponding endportions each having a pair of relatively closely spaced folding creases44 extending thereacross, which creases 44 are parallel with the crease43 adjacent thereto. Each pair of creases 44 divides the end portion inwhich it is formed into a pair of substantially oblong panels 45, 46,with the panel 45 being the one adjoining crease 43.

When the central panel 40 is secured on the bottom panel 2 of the blankof FIG. 1, the panels 45, 46 will be folded to opposed relation alongcreases 44 and each panel 46 will become the inner layer of one of theend walls of the box, while the panel 45 will become the outer layer,and the narrow strip 47 between each pair of creases 44 will be theupper edge of one of said end walls.

The width of each panel 45 in the dimension of the width of the panel40, which is transversely of the length of the latter, is slightlygreater than the width of panel 40, and panel 45 is of the same width upto the folding crease 44that is remote from the central panel 40.

The width of each panel 46, in the dimension of the width .of thecentral panel 40 is slightly greater than the width of panel 45.

The outer free end edges of the main blank of FIG. 3 are the freelongitudinally extending edges of the end panels 46, and are designated48, and the outer corners of each panel 40 are cut off at 43 to have thesame degree of inclination as the degree of inclination of the narrowpanel 4 of the blank of FIG. 1 when the box is assembled. Also thecorners of panel 45 at the ends of creases 43 in the blank of FIG. 3 arecut off at 50 at a similar angle.

A rectangular opening 53 is formed adjacent to each end of each crease43, which openings extend across the creases and partly into panels 45at one side of each crease, and partly into the central panel 40, withthe major portion of each opening being in the central panel. Theseopenings are equally spaced from the ends of the creases 43.

A pair of tabs 54 is formed in each of the narrow strips 47 between eachpair of creases 44, with the base end of each tab integral with eachpanel 45 along the line of the crease 44 that defines the juncturebetween each panel 44 and each such strip 47. However, the tabs are notcreased along the above-mentioned line of one of the creases 44, hencethe latter creases are interrupted by the tabs. The remainder of tabs 54are free from the portions 47 and the outer free edges of said tabs areslightly short of the openings that are cut in the blank to form thetabs, thereby leaving a slight slot 55 between the outer free edge ofeach tab and a line coincidental with the crease 44 that is remote fromeach panel 45.

The outer free edges 48 of the blank of FIG. 3 are formed withrelatively slight outwardly projecting tabs 56 that are equally spacedfrom the ends of said edges 48.

The spacing between the openings 53 and between tabs 54 and tabs 55 isthe same, and the pairs of said tabs and openings are alignedlongitudinally of the blank of FIG. 3.

In forming the lug box, the central panel 40 of the blank of FIG. 3 isglued against the upper surface of the bottom panel 2 of FIG. 1 (FIG. 5)so that the free side edges of the central panel 40 will besubstantially in registration with the folding creases 1 of the blank ofFIG. 1, and so that the creases 43 of the panel of FIG. 3 will besubstantially in registration with the free edges 5 of the blank of FIG.1.

The panels 13 and 15 of each section 11 are then folded in succession,over the panel 14 with the result that the notches 37 will be inregistration with the openings 39 as seen in the upper right handsection 11 in FIG. 5.

The side panels or side walls 6 may then be swung upwardly to positionssubstantially at right angles to the bottom panel 2 about creases 1, andthen the previously folded panels 13-15 are swung about creases 10 topositions over the central panel 10 and at right angles to the sidewalls 6.

The narrower widths of the side walls 6 between creases it than thewidth of the bottom panel 2 between cuts 17 will result in the assembleder prefolded panels 13-15 drawing the narrow panels 4 to upwardlyinclined positions in which the slanted edges of openings 35 that areformed in panels 13, 14, and which are in registration when the panels13 are folded onto panels 14, will engage the upper surfaces of saidnarrow panels 4 when the assembled sections 11 are swung to positionsover the central panel 44 After the folded sections 11 are swung topositions over the central bottom panel 40, the planes of the outer freesurfaces of the panels 14 of sections 11 will be substan tially inregistration with the folding creases 43. The right hand lower corner ofFIG. 5 shows one of the sections 11 in a position preparatory to beingswung upwardly and over the central bottom panel 40.

Either before or after the sections 11 are swung to positions over thecentral bottom panel 40 each of the tabs 25 on each panel 14 may befolded along creases 27 over the tab 24 that is adjacent thereto, sincethe tabs 24 will be in register with the portions of the tabs 25 thatextend across the pairs of creases 18 when the panels 13, of eachsection 11 are folded over the panel 14 between them. The outer end ofeach tab 24 terminates at the crease lines 2'7 in the adjacent tab 25 toenable each tab 25 to fold over each tab 24.

It is pertinent to note that when each section 11 is swung over thecentral panel 40 the openings 53 will be in registration with thenotches 37 formed in the free edges of the panels 15, and with theequivalent notches formed by openings 39 along creases 16. Also, whenthis is done, the portions of openings 53 that extend into the panels 46will form downwardly opening recesses (FIG. 5) adjacent to each of theends of the panels 46 along their lower edges.

The next step in forming the box is to swing the panels 45 upward andagainst the outer surfaces of the sections 11, which outer surfaces areat the outer sides of the panels 14 of said sections. The panels 46 arethen swung over the upper edges of sections 11 and downwardly to lieagainst the inner surfaces of sections 11, which surfaces are one of thesurfaces of the panels 15. In performing the foregoing step, the tabs25, with the tabs 24 enclosed thereby, as indicated in FIG. 6, willenter and pass through the openings in which the tabs 54 are positioned,and the latter tabs will project upwardly alongside the tabs 25. At thesame time the tabs 56 will spring into openings 53 to hold the panels 46against the sections 11, with said sections disposed between panels 45,46. When the tabs 56 are sprung into the openings 53, they are quitefirmly held so there is little, if any, chance for the panels 45 to bereleased accidentally. The free edges 48 of the panels 45 are snuglyagainst the upper surface of the central panel 4! and the narrow strips47 that are between panels 45, 46 are snugly against the upper edges ofthe folded sections 11.

The box in this form will provide a satisfactory box, independently ofthe top panels 3 that are carried by the side walls 6, but these sidewalls contribute to greater rigidity by bending the tabs 32 to positionsat right angles to the panels 8, and projecting toward each other whenpanels 8 are vertical, so that said tabs will enter the openings thatinterrupt the narrow strip 47 where tabs 51 are formed. When the toppanels, which may be called closure flaps are folded downwardly theywill extend over the upper open side of the box and tabs 32 and panels 3will hold the upper portions of the panels 6 against any tendency toswing or bow outwardly relative to the contents of the box.

In stacking the boxes the upwardly extending projections formed by tabs24, 25, 54 will project into the openings 53 in the box thereabove, andthe slanted panels 4 along the lower corners of the upper box willpermit free ventilation to the upper box through openings 31, and alsothe fact that these panels 4 are inclined will present their blockingventilation through the openings 30 in the lower box, or the box belowthe upper box.

Of material importance is also the fact that there are five layers offiberboard in each of the end walls of each box (FIG. 7), and whichlayers extend to the corners of the box, where corrugated, double facedfiberboard is used, the corrugations in the layers of the sections 11and in the panels 45, 46 between which said sections are held, arevertical, hence present the maximum resistance to distortion or collapseagainst compression due to the loads in boxes superposed above others ina stack.

Where loaded boxes of the type described are held for a moderate lengthof time in a warehouse, and the fiberboard is not treated to resistadsorption of moisture from the atmosphere, the lower boxes Will notcollapse.

Where boxes are to be held for relatively long periods of time, thestructure of FIGS. 2, 4 and 8 may be used.

In this form of the invention, substantially the same blanks areemployed as in FIGS. 1, 3, except that the sections 1.1 are cut offalong parallel lines that are coincidental with the edges of tabs 24, 25that face away from the bottom panel 2, hence the same numbers used indescribing the structures of the blanks of FIGS. 1 and 3 will apply tothe blanks of FIGS. 2, 4 and to the box of FIG. 8, where the structuresare identical.

The portions of panels 13, 14 and 15 that remain in FIGS. 2 and 8 arenumbered 113, 114 and 115 and after cutting off the panels 13, 14, 15 ofFIG. 1, as above described, the openings 39 in the blank of FIG. 1become recesses 139 in FIG. 2.

With respect to the blank of FIG. 4-, this blank is identical with theblank of FIG. 3 except that a rectangular block of wood 100 is gluedagainst the side of each panel 46 in a position to lie between thesections 111, which consist of panels 113, 114, 115, when said sectionsare in folded relation as described with respect to the panels 13-15 ofFIG. 1.

When said panels 113-115 are folded on each other in the same manner asdescribed with respect to panels 13-15 of sections 11, it is apparentthat the space between sections 111 (FIG. 8) will be substantiallygreater than the space between sections 1 (FIG. 6) hence the blocks 100in FIGS. 4, 8 may be relatively long.

The thickness of each block 1% may be approximately the same as thethickness of the sections 111, but since the blocks will take the loadof upper boxes in a stack, the boxes of the structure of FIGS. 2, 4 and8 will retain their stability against collapse for an indefinite periodof time.

The folding of the blanks of FIGS. 2, 4 to form the box of FIG. 8 is thesame as the folding of the blanks of FIGS. 1, 3 to form the box of FIG.6, hence the steps will not be repeated.

From the description of the boxes of FIGS. 6 and 8, it is seen that theboxes in a stack will be held in perfect vertical alignment to preventupsetting of a stack due to inaccurate stacking. The projections formedby the tabs 24, 25, 54 and openings 53 insure this result. In actualpractice the panels 1315 and panels 113-115 are glued together, and whenthe tabs or projections 24 are enclosed by the tabs 25, they insurestrong projections that will not be bent or torn, since each projectionformed thereby consists of three layers of the fiberboard, to saynothing of the tabs 54 that are alongside tabs 25.

Being of two-piece construction, the present box can be laid out to usea minimum of material for applied application to a specific commodityand, if desired, the two portions can be of difierent board weights, forexample, the blank of FIG. 1 could be of heavier weight than the blankof FIG. 3, in order to obtain the benefit of the strong sections 11 thatare on the blank of FIG. 1. There are instances where a lighter weightblank of FIG. 3 may be used but such lighter weight would be inadequateto provide the strength required in the sections 11 and side walls.

The provision of separate blanks 1 and 3, or 2 and 4, provides a box inwhich the length of the corrugations in the side and end walls arevertical, thus providing maximum resistance to compression in both endand side walls, and also the fact that the corrugations in the bottomlayers extend, unbroken, at right angles to each other, insures againstbottom sag under a load.

Furthermore, the employment of the separate blanks, as described,enables the manufacturer to imprint the blank of FIG. 1 as a stock itemfor all customers, to be held in stock, and the blanks of FIG. 3 couldthen be imprinted to customer orders. This would effect a substantialeconomy.

There are many other advantages to be derived from the two-piececonstruction, hence this structure is an important feature of thepresent invention.

I claim:

1. A lug box comprising:

(a) a pair of separate blanks of fiberboard, each having (b)substantially corresponding, horizontally disposed,

rectangular central portions,

() said central portions being secured together with their edgessubstantially in registration to provide a pair of bottom panels, onebeing an upper panel and the other being a lower panel,

(d) a pair of vertically disposed opposed end walls integral with onepanel of said bottom panels;

(e) a pair of vertically disposed opposed side walls integral with theother panel of said bottom panels;

(f) said end walls being portions of one panel of said pair folded onthemselves to provide an inner layer and an outer layer of fiberboardrelative to the inside of said box with said inner layer and said outerlayer at each end of the box integrally joined along a fold linedefining the upper edge of each end wall;

(g) means integrally connecting said side walls with said other panel ofsaid bottom panels comprising relatively narrow panels extendingslantingly upwardly and outwardly relative to each other from said otherpanel of said bottom panels to said side walls,

(h) ventilating openings formed in said narrow panels,

(i) means integral with said side walls at their lower ends positionedat right angles to said side walls and disposed between the inner andouter layers of said end walls against which said narrow panels are heldin their said slanted positions, and

(j) interlocking means at the upper edges of said end walls andintegrally connected with said side walls for holding said side wallsvertical and for holding said narrow panels in their said inclinedpositions,

(k) said inner layer of each end wall and the means integral with saidside walls against which said narrow panels are held being disposed overand substantially in engagement with the uppermost of said bottom panelsfor supporting the box against collapse from superimposed loads.

(a) a pair of separate blanks of fiberboard, each having;

(b) a substantially corresponding, horizontally disposed, rectangularcentral portion;

(c) central portions being secured together with their edgessubstantially in registration to provide a pair of bottom panels, onebeing an upper panel and the other being a lower panel;

(d) a pair of vertically disposed opposed end walls integral with onepanel of said bottom panels;

(:2) a pair of vertically disposed opposed side walls integral with theother panel of said bottom panels;

(f) said end walls being portions of one panel of said pair folded onthemselves to provide an inner layer and an outer layer of fiberboardrelative to the inside of said box with said inner layer and said outerlayer at each end of the box integrally joined along a fold linedefining the upper edge of each end wall;

(g) extensions integral with said side walls at the corners of said boxdisposed between said inner and outer layers of said end walls;

(11) interlocking means respectively on said extensions and on said endwalls at the junctures between said inner and outer layers ininterlocking relation for holding said side Walls vertical and againstmovement from between said inner and outer layers;

(i) closure flaps integral with said side walls along their upper edgesextending toward each other and over said bottom panels;

(j) said interlocking means being upward projections on said extensionssubstantially coplanar therewith, and openings formed in each of saidend walls along said fold line through which said projections extend;

(k) tabs integral with said closure flaps extending at right anglesthereto extending into said openings that are formed in each end wallalong the upper edge of the latter for cooperating with said end wallsto resist outward bowing of the latter under the force of contents ofthe box and to hold said extensions vertical;

(I) said interlocking means being spaced along the upper edge of eachend wall from said side walls.

3. A lug box comprising:

(a) a pair of separate blanks of fiberboard, each having;

(b) a substantially corresponding, horizontally disposed, rectangularcentral portion;

(c) said central portions being secured together with their edgessubstantially in registration to provide a pair of bottom panels, onebeing an upper panel and the other being a lower panel;

(d) a pair of vertically disposed opposed end walls integral with onepanel of said bottom panels;

(e) a pair of vertically disposed opposed side walls integral with theother panel of said bottom panels;

(f) said end walls being portions of one panel of said pair folded onthemselves to provide an inner layer and an outer layer of fiberboardrelative to the inside of said box with said inner layer and said outerlayer at each end of the box integrally joined along a fold linedefining the upper edge of each end wall;

(g) extensions integral with said side walls at the corners of said boxdisposed between said inner and outer layers of said end walls; and

(h) interlocking means respectively on said extensions and on said endwalls at the juncturcs between said inner and outer layers ininterlocking relation for holding said side walls vertical and againstmovement from between said inner and outer layers;

(i) closure flaps integral with said side walls along their upper edgesextending toward each other and over said bottom panels;

(j) said interlocking means being upward projections on said extensionssubstantially coplanar therewith,

' 2. A lug box comprising:

and openings formed in each of said end walls along said fold linethrough which said projections extend; (k) tabs integral with saidclosure flaps extending at right angles thereto extending into saidopenings that are formed in each end wall along the upper edge of thelatter for cooperating with said end walls to resist outward bowing ofthe latter under the force of the contents of the box and to hold saidextensions vertical;

(1) said interlocking means being spaced along the up er edge of eachend wall from said side walls;

(m) said projections extending upwardly above said closure flaps;

(n) openings formed in said bottom panels in vertical alignment belowsaid projections adapted to receive the projections of the lower of apair of vertically aligned superposed boxes of the same structure, in astack thereof.

4. A lug box comprising:

(a) a pair of separate blanks of fiberboard, each having (b) asubstantially corresponding, horizontally disposed rectangular centralportion,

(c) said central portions being secured together with their edgessubstantially in registration to provide a pair of bottom panels, onebeing an upper panel and the other being a lower panel,

(d) a pair of vertically disposed opposed end walls integral with onepanel of said bottom panels;

() a pair of vertically disposed opposed side walls integral with theother panel of said bottom panels;

(f) said end walls being portions of one panel of said pair folded onthemselves to provide an inner layer and an outer layer of fiberboardrelative to the inside of said box with said inner layer and said outerlayer at each end of the box integrally joined along a fold linedefining the upper edge of each end wall;

(g) extensions integral with said side walls at the corners of said boxdisposed between said inner and outer layers of said end walls; and

(h) interlocking means respectively on said extensions and on said endwalls at the junctures between said inner and outer layers ininterlocking relation for holding said side walls vertical and againstmovement'frorn between said inner and outer layers;

(i) said extensions on said side walls extending substantially the fullwidth of said end walls in a direction perpendicular to said bottompanels and comprising multiple layers of the fiberboard supported onsaid horizontally disposed panels atsaid end walls to thereby providesupports for said box at the corners thereof to resist collapse of saidside and end walls under compression from the weight of a load on saidside and end walls;

(j) said interlocking means comprising a pair of opposed upwardprojections respectively on the layers forming each of said extensionsintegrally united at their upper ends whereby each pair of opposedprojections will be held together and whereby the projections of eachpair thereof will reinforce each other against flexing and openingsformed in said end walls along said lines of fold defining the upperedges of i said end walls through which said projections extend.

References Cited in the file of this patent UNITED STATES PATENTS1,886,374 Breton Nov. 8, 1932 1,906,622 Kondolf May 2, 1933 2,246,097lllges June 17, 1941 2,532,085 Carter Nov. 28, 1950 2,594,628 Evans Apr.29, 1952 2,893,621 Harnish July 7, 1959 2,950,852 Hutchison Aug. 30,1960 3,003,676 De Nola Oct. 10, 1961 3,015,431 Muicoy Jan. 2, 1962FOREIGN PATENTS 862,060 Great Britain Mar. 1, 1961 GEORGE O. RALSTON,Primary Examiner.

1. A LUG BOX COMPRISING: (A) A PAIR OF SEPARATE BLANKS OF FIREBOARD,EACH HAVING (B) SUBSTANTIALLY CORRESPONDING, HORIZONTALLY DISPOSED,RECTANGULAR CENTRAL PORTIONS, (C) SAID CENTRAL PORTIONS BEING SECUREDTOGETHER WITH THEIR EDGES SUBSTANTIALLY IN REGISTRATION TO PROVIDE APAIR OF BOTTOM PANELS, ONE BEING AN UPPER PANEL AND THE OTHER BEING ALOWER PANEL, (D) A PAIR OF VERTICALLY DISPOSED OPPOSED END WALLSINTEGRAL WITH ONE PANEL OF SAID BOTTOM PANELS; (E) A PAIR OF VERTICALLYDISPOSED OPPOSED SIDE WALLS INTEGRAL WITH THE OTHER PANEL OF SAID BOTTOMPANELS; (F) SAID END WALLS BEING PORTIONS OF ONE PANEL OF SAID PAIRFOLDED ON THEMSELVES TO PROVIDE AN INNER LAYER AND AN OUTER LAYER OFFIBERBOARD RELATIVE TO THE INSIDE OF SAID BOX WITH SAID INNER LAYER ANDSAID OUTER LAYER AT EACH END OF THE BOX INTEGRALLY JOINED ALONG A FOLDLINE DEFINING THE UPPER EDGE OF EACH END WALL; (G) MEANS INTEGRALLYCONNECTING SAID SIDE WALLS WITH SAID OTHER PANEL OF SAID BOTTOM PANELSCOMPRISING